Revived 1970s commercial building an even smarter energy star

Aorangi house

Aorangi House was once tired and outdated but a green-principled refurbishment led to a 5 star NABERSNZ rating in 2016. Now with even more fine-tuning this has led to a top notch 5.5 star NABERSNZ rating.

The 5.5 stars base building rating means a 20% improvement of energy saving compared with 2016. The increase was down to the utilisation of Beca’s in-house advanced building tuning and continuous monitoring service called B-Tune.

Aorangi House case study [pdf 1 MB]


Situated at 85 Molesworth Street in downtown Wellington, 12-storey Aorangi House is a stylish, contemporary office block - its vibrant checkerboard exterior providing a strong visual statement in its commercial neighbourhood.

Built in 1970 the property had a strong presence for many years but over time its building fabric and internal systems became outmoded.

A multi-million dollar overhaul in 2008 earned a 5 Green Star Design rating and positioned Aorangi House as a success story of rejuvenation, smart energy performance and low greenhouse gas emissions.

Energy efficient features include:

  • Solar louvres – optimised for each orientation – providing shade while allowing daylight and panoramic views.
  • A series of perimeter opening windows – manually operated to aid natural ventilation and suit individual needs. Selected high level windows opening automatically to maintain temperature and air
  • A VRF system (variable refrigerant flow) operating only in high tenant-load areas.
  • Smart heating system controls and energy efficient VRF heat pump heating system.
  • Low flow cisterns, taps and pans.

Company Profiles

The owner and building manager

Anaro Group is a commercial property investment and asset management company which administers 44 entities across New Zealand including bulk retail, industrial, warehousing and logistics, hotels and accommodation. The company has embarked on a portfolio-wide review to ensure sustainability is acore value in its code of corporate social responsibility.

Anaro Group

The consultants

Engineering and related services consultancy Beca is an employee-owned company with an Asian Pacific focus in the key hubs of New Zealand, Australia and Singapore. Beca uses the power of partnerships with its clients to think, design and develop creative solutions together. It encourages clients to aim high with sustainability aspirations and in response aims to deliver exemplar green outcomes.

In 2016 Beca achieved a 4.5 star NABERSNZ ‘excellent’ tenancy rating at Aorangi House – gauging the energy use of office equipment and lighting over the nine floors it occupies.


Big Numbers

  • 2010 – Aorangi House achieves 5 Green Star Design rating
  • 2016 – achieves a 5 star NABERSNZ base building rating
  • 2016 – anchor tenant Beca achieves a 4.5 star NABERSNZ tenancy rating
  • 2017 – achieves a 5.5 star NABERSNZ base building rating
  • Total energy consumption 203,174 kWh/year
  • Energy performance is over 64 percent better than an average New Zealand office block